Caltech geochemist Clair Patterson (1922–1995) helped galvanize the environmental movement 50 years ago when he announced that highly toxic lead could be found essentially everywhere on Earth, including in our own bodies—and that very little of it was due to natural causes.

Associate Professor of Astronomy Dimitri Mawet, who recently joined Caltech from the Paranal Observatory in Chile, searches for solar systems around other stars, and hopes to one day discover a planet much like our own.